Local authorities in Sydney are to step up security patrols around a rare breeding colony of Little Penguins after eight of the birds were killed in a recent dog attack.

The colony in the suburb of Manly has only 78 breeding pairs left, and is the last remaining on the mainland of the state of New South Wales.

These penguins tend to have the same mate for life and so an attack of this nature can really have serious long-term impacts

State Environment Minister Bob Debus

Council rangers in Manly plan to set up dawn and dusk patrols, and will round up unleashed dogs from now on, the Associated Press news agency reported.

Wild animal control programmes will also be increased to stem numbers of potential predators such as foxes.

State Environment Minister Bob Debus warned that owners of dogs which attack the penguins could face a maximum sentence of a $110,000 fine and two years in prison.

"These penguins tend to have the same mate for life and so an attack of this nature can really have serious long-term impacts on what was a previously stable population of birds," Mr Debus told parliament.

Endangered

For many years, the authorities and local residents in Manly have fought to conserve the penguins, which are under constant threaten from human activity and animals.

The colony - which 50 years ago had hundreds of birds - has been listed as an endangered population.

Little Penguins - also known as Little Blue Penguins or Fairy Penguins - are found on islands off Australia's southern coast.

They remain a tourist attraction at Phillip Island, in Victoria.

The smallest of the species, at only 40cm high, they usually have dark blue plumage.